arch/mips/sgi-ip32/ip32-reset.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2001 Keith M Wesolowski
   7  * Copyright (C) 2001 Paul Mundt
   8  * Copyright (C) 2003 Guido Guenther <agx@sigxcpu.org>
   9  */
  10
  11 #include <linux/compiler.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/sched.h>
  16 #include <linux/sched/signal.h>
  17 #include <linux/notifier.h>
  18 #include <linux/delay.h>
  19 #include <linux/rtc/ds1685.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/pm.h>
  22
  23 #include <asm/addrspace.h>
  24 #include <asm/irq.h>
  25 #include <asm/reboot.h>
  26 #include <asm/wbflush.h>
  27 #include <asm/ip32/mace.h>
  28 #include <asm/ip32/crime.h>
  29 #include <asm/ip32/ip32_ints.h>
  30
  31 #define POWERDOWN_TIMEOUT       120
  32 /*
  33  * Blink frequency during reboot grace period and when panicked.
  34  */
  35 #define POWERDOWN_FREQ          (HZ / 4)
  36 #define PANIC_FREQ              (HZ / 8)
  37
  38 extern struct platform_device ip32_rtc_device;
  39
  40 static struct timer_list power_timer, blink_timer;
  41 static unsigned long blink_timer_timeout;
  42 static int has_panicked, shutting_down;
  43
  44 static __noreturn void ip32_poweroff(void *data)
  45 {
  46         void (*poweroff_func)(struct platform_device *) =
  47                 symbol_get(ds1685_rtc_poweroff);
  48
  49 #ifdef CONFIG_MODULES
  50         /* If the first __symbol_get failed, our module wasn't loaded. */
  51         if (!poweroff_func) {
  52                 request_module("rtc-ds1685");
  53                 poweroff_func = symbol_get(ds1685_rtc_poweroff);
  54         }
  55 #endif
  56
  57         if (!poweroff_func)
  58                 pr_emerg("RTC not available for power-off.  Spinning forever ...\n");
  59         else {
  60                 (*poweroff_func)((struct platform_device *)data);
  61                 symbol_put(ds1685_rtc_poweroff);
  62         }
  63
  64         unreachable();
  65 }
  66
  67 static void ip32_machine_restart(char *cmd) __noreturn;
  68 static void ip32_machine_restart(char *cmd)
  69 {
  70         msleep(20);
  71         crime->control = CRIME_CONTROL_HARD_RESET;
  72         unreachable();
  73 }
  74
  75 static void blink_timeout(struct timer_list *unused)
  76 {
  77         unsigned long led = mace->perif.ctrl.misc ^ MACEISA_LED_RED;
  78         mace->perif.ctrl.misc = led;
  79         mod_timer(&blink_timer, jiffies + blink_timer_timeout);
  80 }
  81
  82 static void ip32_machine_halt(void)
  83 {
  84         ip32_poweroff(&ip32_rtc_device);
  85 }
  86
  87 static void power_timeout(struct timer_list *unused)
  88 {
  89         ip32_poweroff(&ip32_rtc_device);
  90 }
  91
  92 void ip32_prepare_poweroff(void)
  93 {
  94         if (has_panicked)
  95                 return;
  96
  97         if (shutting_down || kill_cad_pid(SIGINT, 1)) {
  98                 /* No init process or button pressed twice.  */
  99                 ip32_poweroff(&ip32_rtc_device);
 100         }
 101
 102         shutting_down = 1;
 103         blink_timer_timeout = POWERDOWN_FREQ;
 104         blink_timeout(&blink_timer);
 105
 106         timer_setup(&power_timer, power_timeout, 0);
 107         power_timer.expires = jiffies + POWERDOWN_TIMEOUT * HZ;
 108         add_timer(&power_timer);
 109 }
 110
 111 static int panic_event(struct notifier_block *this, unsigned long event,
 112                        void *ptr)
 113 {
 114         unsigned long led;
 115
 116         if (has_panicked)
 117                 return NOTIFY_DONE;
 118         has_panicked = 1;
 119
 120         /* turn off the green LED */
 121         led = mace->perif.ctrl.misc | MACEISA_LED_GREEN;
 122         mace->perif.ctrl.misc = led;
 123
 124         blink_timer_timeout = PANIC_FREQ;
 125         blink_timeout(&blink_timer);
 126
 127         return NOTIFY_DONE;
 128 }
 129
 130 static struct notifier_block panic_block = {
 131         .notifier_call = panic_event,
 132 };
 133
 134 static __init int ip32_reboot_setup(void)
 135 {
 136         /* turn on the green led only */
 137         unsigned long led = mace->perif.ctrl.misc;
 138         led |= MACEISA_LED_RED;
 139         led &= ~MACEISA_LED_GREEN;
 140         mace->perif.ctrl.misc = led;
 141
 142         _machine_restart = ip32_machine_restart;
 143         _machine_halt = ip32_machine_halt;
 144         pm_power_off = ip32_machine_halt;
 145
 146         timer_setup(&blink_timer, blink_timeout, 0);
 147         atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
 148
 149         return 0;
 150 }
 151
 152 subsys_initcall(ip32_reboot_setup);